Plessis develops sensor solution to monitor driver fatigue

Based on its award-winning EPIC sensor technology, Pulse has developed a new solution for monitoring driver fatigue. Research by the Royal College of Traffic Accident Prevention in the UK shows that 20% of traffic accidents and up to a quarter of fatal major traffic accidents are caused by driver fatigue. Therefore, the safety of the car will be a particularly important selling point, and car manufacturers are constantly looking for ways to make safer vehicles.

Traditionally, heart rate is measured in a car using a pair of gel-coated electrodes placed on the chest of the person being measured. The EPIC sensor uses electrodes that do not require contact with the skin, but can actually measure through regular clothing and seat cover materials. By monitoring the heart rate variability (HRV) parameter - which measures each heartbeat to calculate heart rate stability - the car can send a warning notification to the driver when the driver begins to fatigue.

The solution from Pless recommends building a row of sensors into the seat back so that the sensors can select the best measurement position for drivers of any height and body shape. By placing the sensors under the seat back away from the shoulders, the solution can minimize the noise generated by body movement. The system uses a capacitive drive ground layer, which can also be placed under the seat cover of the seat surface, so that a completely hidden system can be constructed. If this drive ground layer is connected to the steering wheel, the noise can be further reduced. The system has been proven to be completely unaffected by electrical noise sources in the car.

Pulex can now provide development tools to automakers and suppliers. The development tools include a seat back pad with six sensors placed on the back of the seat and a ground plane placed on the seat. At the same time, the demonstration kit also includes an interface box with USB output for display and software recording. Pulex's tests show that under various driving conditions, more than 95% of the heart beat peaks can be successfully detected during the ten-minute test.